A mitochondrial ubiquinone; reduces the incidence of ischemia and reperfusion-induced arrhythmia and improves post-ischemic heart rate, coronary flow, aortic flow, and left ventricular developed pressure in isolated guinea pig hearts at 5 mg/kg; reduces ischemia and reperfusion-induced myocardial infarct size and the number of apoptotic cardiomyocytes in the same model at 5 mg/kg